Composition for manufacturing contact lenses and method for manufacturing contact lenses by using the same

ABSTRACT

Methods for manufacturing contact lenses are provided. In an embodiment, the method includes mixing a siloxane macromer represented by the following formula (I), a hydrophilic monomer, a crosslinking agent or a siloxane macromer represented by the following formula (II), and an initiator to form a mixture. Then the mixture is injected into a mold of contact lens and heated to form contact lenses. The formula (I) and the formula (II) are shown respectively as the following: 
                         
wherein R1, R2 and R3 are independently C1-C4 alkyl groups, R4 is C1-C6 alkyl group, R5 is a residue obtained by removing NCO group from an aliphatic or aromatic diisocyanate, R6 and R7 are independently alkylene groups, and n is an integer of 4-80, m is an integer of 3-40.
 
                         
wherein p is an integer of 4-80 and q is an integer of 3-40.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional of the application Ser. No.14/726,592 filed on May 31, 2015, now U.S. Pat. No. 9,527,251, which isa divisional of the application Ser. No. 13/488,420 filed on Jun. 4,2012, now U.S. Pat. No. 9,523,793, and claims priority under 35 U.S.C.119(e) to Taiwanese application serial number 100131653 filed on Sep. 2,2011 the entire contents of which are hereby incorporated herein byreference.

BACKGROUND Field of Invention

The present invention relates to a composition for manufacturing contactlenses. More particularly, the present invention relates to acomposition for manufacturing contact lenses comprising hydrophilicsiloxane macromer.

Description of Related Art

The hydrogel contact lenses are made from hydrogel materials, such aspoly-2-hydroxyethyl methacrylate (p-HEMA), and the strength of2-hydroxyethyl methacrylate (HEMA) can be improved by addingcrosslinking agent like ethylene glycol dimethacryate (EGDMA). Since thewater content of the HEMA is only about 38.8% the hydrophilic monomer,for example N-vinylpyrrolidone, N,N-dimethylacrylamide and methylacrylic acid, is added to improve the water content of such materialsfor the contact lenses. With the addition of the hydrophilic monomer,the water content of the contact lenses can increase up to 80%. However,the higher water content of the contact lenses is, the lower tension andtoughness thereof become. The water content of contact lenses generallyranges from about 45% to 58%, but the real oxygen permeability can onlyreach about 15-35 regardless the further improvement of the watercontent.

Silicone hydrogel contact lenses have better oxygen permeability thanhydrogel contact lenses. Silicone hydrogel contact lenses comprises asilicone polymeric material which was made by polymerizing two siloxanemacromers, which have different chemical structures and differentmolecular weights, and a hydrophilic monomer, such as N-vinylpyrrolidone(NVP), methyl acrylic acid and N,N-dimethylacrylamide.

However, because of the hydrophobic characteristic on the surface ofsilicone hydrogel contact lenses, it is apt to incur the bacteria breedand eyes irritation. Therefore, an object of the present invention is toprovide a composition of contact lenses and a method for manufacturingcontact lenses by using the same to surmount the aforesaid disadvantagesof the prior art.

SUMMARY

According to an aspect of the present invention, a composition formanufacturing contact lenses is provided.

In an embodiment of the present invention, the composition formanufacturing contact lenses comprises a siloxane macromer representedby the following formula (I), a hydrophilic monomer, a crosslinkingagent and an initiator. The formula (I) is

wherein R1, R2 and R3 are independently C1-C4 alkyl groups, R4 is C1-C6alkyl group, R5 is a residue obtained by removing NCO group from analiphatic or aromatic diisocyanate, R6 and R7 are independently alkylenegroups, and n is an integer of 4-80, m is an integer of 3-40, and themolecular weight of the siloxane macromer of formula (I) is 1,000 to10,000.

In an embodiment of the present composition for manufacturing contactlenses, the hydrophilic monomer is selected from a group consisting of2-hydroxyethyl methacrylate (HEMA), N-vinylpyrrolidone (NVP), methylacrylic acid, acrylic acid, glycidyl methacrylate, (methyl) acrylamide,N,N-dimethylacrylamide, vinyl bamate and a combination thereof.

In another embodiment of the present composition for manufacturingcontact lenses, the composition for manufacturing contact lensescomprises a siloxane macromer of formula (I) defined as above, ahydrophilic monomer a siloxane macromer represented by the followingformula (II) and an initiator. The formula (II) is

wherein p an integer of 4-80 and q is an integer of 3-40.

According to a further aspect of the present invention, the compositionfor manufacturing contact lenses comprises a siloxane macromer offormula (I) defined as above a hydrophilic monomer, a siloxane macromerof formula (II) defined as above, a crosslinking agent and an initiator.

According to a further another aspect of the present invention, a methodfor manufacturing the contact lenses is provided.

In an embodiment of the method of the present invention, the method formanufacturing the contact lenses comprises the following steps. First, asiloxane macromer of formula (I) defined as above, a hydrophilicmonomer, a crosslinking agent and an initiator are mixed to form amixture. Then, the mixture is injected into a mold of contact lens andheated to form contact lenses.

In another embodiment of the method of the present invention, the methodfor manufacturing the contact lenses comprises the following steps.First, siloxane macromer of formula (I) defined as above, a hydrophilicmonomer, a siloxane macromer of formula (II) defined as above and aninitiator are mixed to form a mixture. Then, the mixture is injectedinto a mold of contact lens and heated to form contact lenses.

In still another embodiment of the method of the present invention, themethod for manufacturing the contact lenses comprises the followingsteps. First, a siloxane macromer of formula (I) defined as above, ahydrophilic monomer, a siloxane macromer of formula (II) defined asabove, a crosslinking agent and an initiator are mixed to form amixture. Then, the mixture is injected into a mold of contact lens andheated to form contact lenses.

The above and other aspects of the invention will become betterunderstood with regard to the following detailed description of thepreferred but nonlimiting embodiment(s).

DETAILED DESCRIPTION

Accordingly, a composition for manufacturing contact lenses and a methodfor manufacturing contact lenses by using the same are provided. In thefollowing detailed description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. It will be apparent,however, that one or more embodiments may be practiced without thesespecific details.

According to an aspect of the present invention, a composition formanufacturing contact lenses is provided. The contact lenses havehydrophilic surface, excellent oxygen permeability and high watercontent.

In an embodiment of the present invention, the composition formanufacturing contact lenses comprises a siloxane macromer representedby the following formula (I), a hydrophilic monomer, an initiator and acrosslinking agent or a siloxane macromer represented by the followingformula (II), wherein the formula (I) is

wherein R1, R2 and R3 are independently C1-C4 alkyl groups, R4 is C1-C6alkyl group, R5 is a residue obtained by removing NCO group from analiphatic or aromatic diisocyanate, R6 and R7 are independently alkylenegroups, and n is an integer of 4-80, m is an integer of 3-40 and themolecular weight of the siloxane macromer of formula (I) is 1,000 to10,000.

And the formula (II) is

wherein p is an integer of 4-80, q is an integer of 3-40.

The hydrophilic monomer is selected from a group consisting of2-hydroxyethyl methacrylate (HEMA), N-vinylpyrrolidone (NVP), methylacrylic acid, acrylic acid, glycidyl methacrylate, (methyl) acrylamide,N,N-dimethylacrylamide, vinyl bamate and a combination thereof. In anembodiment of composition for manufacturing contact lenses of thepresent invention, the hydrophilic monomer is a combination of HEMA andNVP.

In addition, the siloxane macromer of formula (II) defined as aboveprovides a crosslinking function. In an embodiment of composition formanufacturing contact lenses of the present invention, the presentcomposition comprises one of the siloxane macromer of formula (II) and acrosslinking agent. In another embodiment of composition formanufacturing contact lenses of the present invention, the presentcomposition for manufacturing contact lenses comprises both the siloxanemacromer of formula (II) and a crosslinking agent.

In an embodiment of composition for manufacturing contact lenses of thepresent invention, the siloxane macromer of formula (I) comprises butnot limited to a siloxane macromer represented by the following formula(III):

wherein r is an integer of 4-80 and s is an integer of 3-40.

Moreover, the crosslinking agent suitably used in conventionalcompositions for manufacturing contact lenses can be used in thecomposition of the present invention, such as, for example, ethyleneglycol dimethacrylate (EGDMA), tetraethylene ethylene glycoldimethacrylate (TEGDMA), tetraethylene ethylene glycol dimethacrylate(TrEGDMA), Poly(ethylene glycol) dimethacrylate, trimethylolpropanetrimethacrylate, vinyl methacrylate, ethylenediamine dimethylacrylamide, glycerol dimethacrylate, triallyisocyanurate or triallylcyanurate. In a preferred embodiment of composition for manufacturingcontact lenses of the present invention, the crosslinking agent isEGDMA.

The initiator suitably used in conventional compositions formanufacturing contact lenses can be used in the composition of thepresent invention, such as, for example, azobisisoheptonitrile (ADVN),2,2′-azobis(isoheptonitrile) (AIBN),2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobis(2-methyl-propanenitrile),2,2′-azobis(2-methyl-butanenitrile) or benzoyl peroxide. In a preferredembodiment of composition for manufacturing contact lenses of thepresent invention, the initiator is ADVN.

In an embodiment of composition for manufacturing contact lenses of thepresent invention, the composition of contact lenses comprises asiloxane macromer of formula (I) defined as above, a hydrophilicmonomer, a crosslinking agent and an initiator. In the composition ofthis embodiment, the siloxane macromer of formula (I) is present at anamount of 30 to 40 parts by weight, the hydrophilic monomer is presentat an amount of 40 to 65 parts by weight, the crosslinking agent ispresent at an amount of 1 to 10 parts by weight and the initiator ispresent at an amount of 0.1 to 1 parts by weight based on the totalamount of the composition. Furthermore, the hydrophilic monomer used inthis embodiment is a combination of HEMA and NVP, wherein the HEMA ispresent at an amount of 1 to 5 parts by weight and the NVP is present atan amount of 40 to 60 parts by weight based on the total amount of thecomposition.

In another embodiment of composition for manufacturing contact lenses ofthe present invention, the composition for manufacturing contact lensescomprises a siloxane macromer of formula (I) defined as above ahydrophilic monomer, a crosslinking agent, an initiator and a siloxanemacromer of formula (II) defined as above. In this embodiment, thesiloxane macromer of formula (I) is present at an amount of 20 to 45parts by weight, the hydrophilic monomer is present at an amount of 40to 75 parts by weight, the crosslinking agent is present at an amount of1 to 5 parts by weight, the siloxane macromer of formula (II) is presentat an amount of 5 to 20 parts by weight and the initiator is present atan amount of 0.1 to 1 parts by weight based on the total amount of thecomposition. Furthermore, the hydrophilic monomer used in thisembodiment is a combination of HEMA and NVP, wherein the HEMA is presentat an amount of 1 to 20 parts by weight and the NW is present at anamount of 40 to 55 parts by weight based on the total amount of thecomposition.

According to another aspect of the present invention, a composition formanufacturing contact lenses is provided. The contact lenses havehydrophilic surface, excellent oxygen permeability and high watercontent.

In an embodiment of composition for manufacturing contact lenses of thepresent invention, the composition of contact lenses comprises asiloxane macromer of formula (I) defined as above, a hydrophilicmonomer, an initiator and a siloxane macromer of formula (II) defined asabove. In the composition of this embodiment the siloxane macromer offormula is present at an amount of 15 to 45 parts by weight, thehydrophilic monomer is present at an amount of 40 to 75 parts by weight,the siloxane macromer of formula (II) is present at an amount of 5 to 30parts by weight and the initiator is present at an amount of 0.1 to 1parts by weight based on the total amount of the composition.Furthermore, the hydrophilic monomer used in this embodiment is acombination of HEMA and NVP, wherein the HEMA is present at an amount of1 to 15 parts by weight and the NVP is present at an amount of 40 to 60parts by weight based on the total amount of the composition.

In addition, the composition for manufacturing contact lenses canfurther comprise but not limited to a dye and an anti-UV agent.

According to a further aspect of the present invention, a method formanufacturing contact lenses is provided. The contact lenses made by thepresent method have hydrophilic surface, excellent oxygen permeabilityand high water content. The method can comprise but not limited to thefollowing steps.

First, a siloxane macromer represented by the following formula (I), ahydrophilic monomer, an initiator and a crossling agent or a siloxanemacromer represented by the following formula (II) are mixed to form amixture. Then, the mixture is injecting into a mold of contact lens andheating the mixture to form contact lenses. The molecular weight of thesiloxane macromer of formula (I) is 1,000 to 10,000. The formula (I) is

wherein R1, R2 and R3 are independently C1-C4 alkyl groups, R4 is C1-C6alkyl group, R5 is a residue obtained by removing NCO group from analiphatic or aromatic diisocyanate, R6 and R7 are independently alkylenegroups, and n is an integer of 4-80, m is an integer of 3-40;and the formula (II) is

wherein p is an integer of 4-80 and q is an integer of 3-40,

The hydrophilic monomer is selected from a group consisting of2-hydroxyethyl methacrylate (HEMA), N-vinylpyrrolidone (NVP), methylacrylic acid, acrylic acid, glycidyl methacrylate, (methyl)acrylamide,N,N-dimethylacrylamide, vinyl bamate and a combination of said materialsthereof. In an embodiment of the method of the present invention, thehydrophilic monomer is a combination of HEMA and NVP.

In addition, the siloxane macromer of formula (II) provides acrosslinking function. In an embodiment of the method of the presentinvention, the mixture comprises one of the siloxane macromer of formula(II) and crosslinking agent. In another embodiment of the method of thepresent invention, the mixture comprises both the siloxane macromer offormula (II) and crosslinking agent.

In an embodiment of the method of the present invention, the siloxanemacromer of formula (I) comprises but not limited to a siloxane macromerrepresented by the following formula (III):

wherein r is an integer of 4-80 and s is an integer of 3-40.

Moreover, the crosslinking agent suitably used in conventionalcompositions for manufacturing contact lenses can be used in the methodof the present invention, such as, for example, ethylene glycoldimethacrylate (EGDMA), tetraethylene ethylene glycol dimethacrylate(TEGDMA), tetraethylene ethylene glycol dimethacrylate (TrEGDMA),Poly(ethylene glycol) dimethacrylate, trimethylolpropanetrimethacrylate, vinyl methacrylate, ethylenediamine dimethylacrylamide, glycerol dimethacrylate, triallyisocyanurate or triallylcyanurate. In a preferred embodiment of the method of the presentinvention, the crosslinking agent is ethylene glycol dimethacrylate(EGDMA).

Besides, the initiator suitably used in conventional compositions formanufacturing contact lenses can be used in the method of the presentinvention, such as, for example, azobisisoheptonitrile (ADVN),2,2′-azobis(isoheptonitrile) (AIBN),2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobis(2-methyl-propanenitrile),2,2′-azobis(2-methyl-butanenitrile) or benzoyl peroxide. In a preferredembodiment of the method of the present invention, the initiator isADVN.

In an embodiment of the method of the present invention, the step offorming the mixture comprises mixing a siloxane macromer of formula (I)defined as above, a hydrophilic monomer, a crosslinking agent and aninitiator to form a mixture. In the method of this embodiment, thesiloxane macromer of formula (I) is present at an amount of 30 to 40parts by weight, the hydrophilic monomer is present at an amount of 40to 65 parts by weight, the crosslinking agent is present at an amount of1 to 10 parts by weight and the initiator is present at an amount of 0.1to 1 parts by weight based on the total amount of the mixture.Furthermore, the hydrophilic monomer used in this embodiment is acombination of HEMA and NVP, wherein the HEMA is present at an amount of1 to 5 parts by weight and the NVP is present at an amount of 40 to 60parts by weight based on the total amount of the mixture.

In another embodiment of the method of the present invention, the stepof forming the mixture further comprises mixing a siloxane macromer offormula (I) defined as above, a hydrophilic monomer, a crosslinkingagent, an initiator and a siloxane macromer of formula (II) defined asabove to form the mixture. In the method of this embodiment, thesiloxane macromer of formula (I) is present at an amount of 20 to 45parts by weight, the hydrophilic monomer is present at an amount of 40to 75 parts by weight, the crosslinking agent is present at an amount of1 to 5 parts by weight, the siloxane macromer of formula (II) is presentat an amount of 5 to 20 parts by weight and the initiator is present atan amount of 0.1 to 1 parts by weight based on the total amount of themixture. Furthermore, the hydrophilic monomer used in this embodiment isa combination of HEMA and NVP, wherein the HEMA is present at an amountof 1 to 20 parts by weight and the NVP is present at an amount of 40 to55 parts by weight based on the total amount of the mixture.

In still another embodiment of the method of the present invention, thestep of forming the mixture comprises mixing a siloxane macromer offormula (I) defined as above, a hydrophilic monomer, an initiator and asiloxane macromer of formula (II) defined as above to form the mixture.In the method of this embodiment, the siloxane macromer of formula (I)is present at an amount of 15 to 45 parts by weight, the hydrophilicmonomer is present at an amount of 40 to 75 parts by weight, thesiloxane macromer of formula (II) is present at an amount of 5 to 30parts by weight and the initiator is present at an amount of 0.1 to 1parts by weight based on the total amount of the mixture. Furthermore,the hydrophilic monomer used in this embodiment is a combination of HEMAand NVP, wherein the HEMA is present at an amount of 1 to 15 parts byweight and the NVP is present at an amount of 40 to 60 parts by weightbased on the total amount of the mixture.

In addition, the mixture could further comprise but not limited to a dyeand an UV-blocking agent or other materials suitable used in the priorcontact lenses for providing specific functions.

After forming the mixture, the mixture is injected into a mold ofcontact lens and heating the mixture to form contact lenses.

The heating treatment is conducted at a temperature in the range betweenabout 30° C. to about 150° C., the reaction time is in the range fromabout 1 hour to 12 hours. In an embodiment of the method of the presentinvention, the heating treatment is conducted at 30-70° C. for 0-2hours, 70-100° C. for 2-4 hours and 100-150° C. for 4-12 hours.

After the heating treatment, the method of the present invention canfurther comprise a water-imparting treatment. In an embodiment of themethod of the present invention, the water-imparting treatment comprisesbut not limited to the following steps.

Firstly, the contact lenses are soaked in alcohol solution, then soakedin water, and finally soaked in a buffer solution to be equilibria.

The water content of the contact lenses according to the presentinvention is in the range of about 25% to 55%, and preferably in therange of 35% to 55%.

Additionally, the oxygen permeability of the contact lenses according tothe present invention is more than 80, and preferably more than 100.

The present invention will be explained in further detail with referenceto the examples. However, the present invention is not limited to theseexamples.

EXAMPLE

1. Synthesis of a siloxane macromer

A. Synthesis of siloxane macromer (A)

(1) The reaction scheme siloxane macromer (A) is shown as follow:

(2) Preparation of siloxane macromer (A)

4.44 g of isophorone diisocyanate, 0.0025 g of dibutyltin dilaurate asthe catalyst, and 40 mL of methylene chloride were added to a flask, andthe solution stirred under a stream of nitrogen. Then, 20 g ofα-butyl-ω-[3-(2,2-(dihydroxymethyl)butoxy)propyl]polydimethylsiloxanewas accurately weighed and added dropwise to the solution over about 1hour. After the reaction at room temperature for 12 hours, another0.0025 g of dibutyltin dilaurate and 7.2 g of polyethylene glycolmonomethacrylate were accurately weighed and added dropwise to thesolution over about 1 hour. After the reaction is conducted at roomtemperature for another 12 hours, the resulting reaction product waswashed with a large amount of water, and then dehydrated and filtered toobtain the raw product. Then, the methylene chloride was evaporated toobtain a siloxane macromer (A).

(3) The properties of siloxane macromer (A)

-   -   IR spectroscopy:        -   (i) Absorption bands derived from Si—CH₃ at 802 cm⁻¹ and            1259 cm⁻¹.        -   (ii) An absorption band derived from Si—O—Si at 1032 cm⁻¹            and 1100 cm⁻¹.        -   (iii) An absorption band derived from C═O of methacryloyl            group at 1720 cm⁻¹.    -   NMR spectroscopy:        -   (i) A peak derived from Si—CH₃ at around 0.1 ppm.        -   (ii) A peak of methyl protons derived from isophorone            diisocyanate at around from 0.8 to 1.2 ppm.        -   (iii) A peak derived from methyl protons of methacryloyl            group at around 1.92 ppm.        -   (iv) A peak of vinyl protons of methacryloyl group at around            5.55 ppm and 6.11 ppm.

B. Synthesis of siloxane macromer (B)

(1) The reaction scheme of siloxane macromer (B) is shown as follow:

(2) The preparation of siloxane macromer (B)

8.88 g of isophorone diisocyanate, 0.0025 g of dibutyltin dilaurate asthe catalyst, and 40 mL of methylene chloride were added to a flask, andthe solution was stirred under a stream of nitrogen. Then, 20 g ofα-butyl-ω-[3-(2,2-(dihydroxymethyl)butoxy)propyl]polydimethylsiloxanewas accurately weighed and added dropwise to the solution over about 1hour. After the reaction at room temperature for 12 hours, another0.0025 g of dibutyltin dilaurate and 14.4 g of polyethylene glycolmonomethacrylate were accurately weighed and added dropwise to thesolution over about 1 hour. After the reaction at room temperature foranother 12 hours, the resulting reaction product was washed with a largeamount of water, and then dehydrated and filtered to obtain a rawproduct. Then, the methylene chloride was evaporated to obtain asiloxane macromer (B).

(3) The properties of siloxane macromer (B)

-   -   IR spectroscopy:        -   (iv) Absorption bands derived from Si—CH₃ at 802 cm⁻¹ and            1259 cm⁻.        -   (v) An absorption band derived from Si—O—Si at 1032 cm⁻¹ and            1100 cm⁻¹.        -   (vi) An absorption band derived from C═O of methacryloyl            group at 1720 cm⁻¹.    -   NMR spectroscopy:        -   (v) A peak derived from Si—CH₃ at around 0.1 ppm.        -   (vi) A peak of methyl protons derived from isophorone            diisocyanate at around from 0.8 to 1.2 ppm.        -   (vii) A peak derived from methyl protons of methacryloyl            group at around 1.92 ppm.        -   (viii) A peak of vinyl protons of methacryloyl group at            around 5.55 ppm and 6.11 ppm.

2. Preparation of contact lenses

(1) The preparation steps

A siloxane macromer and a hydrophilic monomer were mixed as the weightpercentages shown in Table 1, and a dye and an UV-blocking agent wereadditionally added to make the contact lenses easily to be recognizedand prevent UV light. The initiator was added into the mixture. Themixture was then injected into a mold of contact lens made ofpolypropylene (PP) and heated to initiate the radical polymerizationthereof to obtain a heat-reaction silicone hydrogel contact lenses withhigh oxygen permeability.

TABLE 1 The recipe of contact lenses according to the present inventionSiloxane macromer (A) 15~60% Siloxane macromer (B)  0~30% NVP 30~75%HEMA EDGMA  0~10% ADVN 0.1~1%  

(2) The preparation of the contact lenses of Example 1-Example 8

A siloxane macrome (A), a siloxane macrome (B), 2-hydroxyethylmethacrylate (HEMA) and N-vinylpyrrolidone (NVP), anazobisisoheptonitrile (ADVN) and an ethylene glycol dimethacrylate(EGDMA) were mixed at the amounts shown in Table 2 for Example 1-Example8, respectively and stirred about 1 hour.

Then, the mixtures were injected into a mold of contact lens made ofpolypropylene (PP) and heated to initiate the radical polymerizationthereof at 60° C. for 1 hour, at 80° C. for 2 hours and then, at 135° C.for 2 hours.

After the polymerization was completed, the mold was immersed in 80%alcohol solution for 1 hour and the resulting molded lens was taken outof the mold. The resulting lens was conducted a hydration treatment toobtain a contact lenses with excellent oxygen permeability. Finally, asterilizing treatment on the lens was conducted. The steps and theconditions of hydration treatment and sterilizing treatment were asfollow:

The steps of hydration treatment of the contact lens

-   -   (a) The mold was immersed in 80% alcohol solution for 1 hour        then the resulting molded lens was taken out of the mold.    -   (b) The polymer resulting molded lens was then immersed in 90%        alcohol solution for 1 hour.    -   (c) The alcohol-immersed contact lens was heated water at 80° C.        for 1 hour.    -   (d) The contact lens was immersed in a buffer solution to obtain        equilibrium.

The conditions of sterilizing treatment: 121° C. for 30 minutes.

TABLE 2 The composition of contact lenses of Example 1-Example 8 Example(wt %) Item Composition Function 1 2 3 4 5 6 7 8 Ingredients SiloxaneSiloxane 20.9 20.9 20.9 41.8 41.8 41.8 38.6 38.8 macromer macromer (A)Siloxane Siloxane 20.9 18.8 16.7 6.3 6.3 6.3 5.8 0 macromer macromer (B)NVP Hydrophilic 51.2 51.2 51.2 44.9 43.9 41.8 41.5 48.5 monomer HEMAHydrophilic 6.3 6.3 6.3 6.3 6.3 6.3 13.5 4.8 monomer EDGMA Crosslinking0 2.1 4.2 0 1 3.1 0 7.3 agent ADVN Initiator 0.7 0.7 0.7 0.7 0.7 0.7 0.70.7 Total 100 100 100 100 100 100 100 100 Total/Solvent Hexanol Solvent25.1 25.1 25.1 25.1 25.1 25.1 9.7 32

(3) Physical property tests

The results of physical property tests of Comparative Example 1(O₂OPTiX, commercially available from Ciba), Comparative Example 2 (PureVision, commercially available from B&L) and Example 1-Example 8 of thepresent invention were shown as the following Table 3.

TABLE 3 The result of physical property tests Comparative ExampleExample Item 1 2 3 4 5 6 7 8 1 2 Water 49.8 34.9 27.3 30.1 48.8 29.253.23 51.5 36 33 content(%) Modulus 0.41 0.4 0.44 0.42 0.41 0.4 0.680.58 1 0.93 (Mpa) Tension 12 15 — 22 14 — 89 37 103 60 (g) Oxygen 11881.8 89 150 138.6 124.3 100 101 75 84 permeability (Dk)

As shown in Table 3, the contact lenses according to the presentinvention have more excellent oxygen permeability than comparativeexamples. Moreover the oxygen permeability of Example 1, Example 4,Example 5, Example 6, Example 7 and Example 8 are higher than 100, andthe oxygen permeability of Example 4 is even up to 150. In addition, thewater content of Example 1, Example 5, Example 7 and Example 8 are morethan 45%, but the water content of Comparative Example 1 and ComparativeExample 2 are only 36% and 33%, respectively.

According to the present invention, the contact lenses have moreexcellent oxygen permeability and water content than the conventionalcontact lenses.

While the invention has been described by way of example(s) and in termsof the preferred embodiment(s) it is to be understood that the inventionis not limited thereto. On the contrary, it is intended to cover variousmodifications and similar arrangements and procedures, and the scope ofthe appended claims therefore should be accorded the broadestinterpretation so as to encompass all such modifications and similararrangements and procedures.

What is claimed is:
 1. A method for manufacturing contact lensescomprising: (a) mixing a siloxane macromer represented by the followingformula (I), a hydrophilic monomer, a crosslinking agent and aninitiator to form a mixture; and (b) injecting the mixture into a moldof contact lens and heating the mixture to form contact lenses; whereinthe molecular weight of the siloxane macromer of formula (I) is 1,000 to10,000:

wherein R1, R2 and R3 are independently C1-C4 alkyl groups, R4 is C1-C6alkyl group, R5 is a residue obtained by removing NCO group from analiphatic or aromatic diisocyanate, R6 and R7 are independently alkylenegroups, and n is an integer of 4-80, m is an integer of 3-40; moreover,the hydrophilic monomer is selected from a group consisting of2-hydroxyethyl methacrylate (HEMA), N-vinylpyrrolidone (NVP), methylacrylic acid, acrylic acid, glycidyl methacrylate, (methyl)acrylamide,N,N-dimethylacrylamide, vinyl bamate and a combination of said materialsthereof.
 2. The method for manufacturing contact lenses according toclaim 1, wherein the hydrophilic monomers is a combination of HEMA andNVP.
 3. The method for manufacturing contact lenses according to claim1, wherein the crosslinking agent is selected from a group consisting ofethylene glycol dimethacrylate (EGDMA), tetraethylene ethylene glycoldimethacrylate (TEGDMA), tetraethylene ethylene glycol dimethacrylate(TrEGDMA), poly(ethylene glycol) dimethacrylate, trimethylolpropanetrimethacrylate, vinyl methacrylate, ethylenediamine dimethylacrylamide, glycerol dimethacrylate, triallyisoeyanurate and triallylcyanurate.
 4. The method for manufacturing contact lenses according toclaim 1, wherein the initiator is selected from a group consisting ofazobisisoheptonitrile (ADVN), 2,2′azobis(isoheptonitrile) (AIBN),2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobis(2-methyl-propanenitrile),2,2′-azobis(2-methyl-butanenitrile) and benzoyl peroxide.
 5. The methodfor manufacturing contact lenses according to claim 1, wherein thesiloxane macromer of formula (I) is present at an amount of 30 to 40parts by weight, the hydrophilic monomer is present at an amount of 40to 65 parts by weight, the crosslinking agent is present at an amount of1 to 10 parts by weight and the initiator is present at an amount of 0.1to 1 parts by weight based on the total amount of the mixture.
 6. Themethod for manufacturing contact lenses according to claim 5, whereinthe hydrophilic monomer is a combination of HEMA and NW, wherein theHEMA is present at an amount of 1 to 20 parts by weight and the NVP ispresent at an amount of 40 to 55 parts by weight based on the totalamount of the mixture.
 7. The method for manufacturing contact lensesaccording to claim 1, wherein the siloxane macromer of formula (I)comprising a siloxane macromer represented by the following formula(III):

wherein r is an integer of 4-80 and s is an integer of 3-40.